Designing Biomass Rice Husk Silica as an Efficient Catalyst for the Synthesis of Biofuel Additive n-Butyl Levulinate

The conversion of lignocellulosic biomass levulinic acid to biorefinery platform organic component n-butyl levulinate is done by an eco-friendly process. The catalyst used for this reaction was prepared by an innovative strategy of impregnating CeO2 and Sm2O3 on silica derived from rice husk, biomass of low economic value, using different methods. The impregnation of ceria and samaria into the silica framework led to a change in the textural properties which was confirmed by various spectroscopic methods. A comprehensive study of the influence of reaction parameters on the esterification of levulinic acid with n-butanol revealed the optimum conditions for maximum yield and selectivity. In the solvent-free condition, the reaction achieved 94.9% conversion of levulinic acid and 97.2% selectivity of n-butyl levulinate within a duration of 1.5 h. The regenerated catalysts were stable and efficient up to four cycles. Graphical